Hello hillb,
Panels are associated with the thread in which they are created. This doesn't mean that you can't access them or their controls, from other threads, including displaying them, but it does mean that you need to run their event loop in the thread with which they're associated, otherwise their UI will freeze.
In your case, since you are loading the panel in the main thread, that main thread needs to be continually calling one of the event processing functions (RunUserInterface, ProcessSystemEvents, GetUserEvent) while that panel is active. Calling these functions in the thread which displays the panel will not be of help.
If you're already doing this, and the problem is something else, please give me some more information about what your code is doing, and we'll see if we can figure out what the problem is.
Luis
